Description: The Cellular Biochemistry and Biophysics Program was established to study basic mechanisms of cell biology using methods of biochemistry and structural biology. During the current funding period, it advanced from a "developing program" to an established program with 11 members. The focus of the research is presented with two major thrusts: (1) tissue architecture and assembly and (2) cell organization and function. Major scientific contributions from this program include the identification of new signaltransducing molecules such as disintegrins or beta-catenin, the elucidation of the role of hsp molecular chaperones in protein folding, the description of mechanisms of vesicle budding, and the elucidation of the structures of the AMP-RNA aptamer complex, the p53-DNA complex and the cyclin A-CDK2 complex. Intra- and interprogrammatic interactions are fostered through a variety of seminars, retreats and frequent informal contact. Program members attend both a program seminar series and a joint series with the structural biology faculty at Rockefeller University and the weekly Work-in-Progress meetings. The Program Leader, Dr. James Rothman, was recruited to MSKCC in 1991 and led the recruitment to assemble the present faculty. Future plans are to add two to three new members with interests in cell signaling, regulation and development.